Adjustable seat mechanism



March 27, 1934. A. w. CHAPMAN ADJUSTABLE SEAT MECHANI ESM Filed Oct. 24, 1931 1.J m z/vm? coda 662mm 015 5y i I My. M

Patented Mar. 27, 1934 ADJUSTABLE SEAT MECHANISM Arthur William Chapman, Putney, London, England Application October 24, 1931, Serial No. 570,870

, In Great Britain November 3, 1930 3 Claims.

An application has been filed in Great Britain No. 33,051 on the 3rd November 1930.

This invention relates to adjustable seat mechanisms, of the kind which are designed either (1) to be raised and lowered for altering the height of the seat or (2) to be slid forwardly and rearwardly or to combine these adjustments. Th seat, in order to be capable of slidable adjustment, is provided with means whereby it can slide upon rails. It is common knowledge that a seat which is adjustable by engagement with slides or rails is liable to jam or cock unless the moving force is applied either simultaneously at :both its sides or at a point located between its sides so that the applied force is evenly distributed. This jamming or cocking is particularly pronounced in the wider type of seats for accommodating two or more persons, and is not altogether absent from the narrower, or single seats, in which there is generally a tendency to bind, which tendency gives rise to undesirable frictional resistance.

According to the present invention, to obviate these difiiculties, certain thrust equalizing levers are provided which extend across from one side of the seat to the other. An actuating mechanism or crank handle, is situated at one side of the seat position, either at the right or the left, as desired. In a preferred form of the invention, for the purpose of raising and lowering the seat of a vehicle such as an automobile or an omnibus, a pair of inter-engaging slides and rails of the nature of channelled strips is provided upon each side of the mechanism, each pair of slides consisting of a channel section slide which can be fastened to the rear or bottom of the seat, and a channel-section rail which can be fastened to the body of the vehicle. The slide and rail are so bent at their respective edges as to provide interengaging slidable connection therebetween and leaving an enclosed box-like space between each slide and rail. Either of these box-like spaces may be utilized to contain the main portion of the slide actuating mechanism, which, for example, comprises an externally threaded rod having a crank or handle projecting at one end. This threaded rod cooperates with an internally threaded block rigidly fastened onto the rail, the rotation of the handle causing the said threaded rod to thread and unthread itself through the block. The rod is fixedly secured to the slide, so that the latter is compelled to travel with it in one direction or the other, according to the direction in which the rod is rotated, and the said slide will be left locked in any position to which it is brought. The power applied to the one slide is distributed between that slide and the slide upon the other side of the mechanism by means of cross-rods pivoted at or near their centre points and extending from one side-to the other and suitably connected at their ends to the slides and rails hereinafter described.

According to the invention, the seat sliding mechanism, though the power to actuate the same is applied at one side only, is operated with equal efiect at both sides of the seat, as a result of an evenly balanced distribution of power. The seat may thereby be adjusted up and down, and by similar mechanism it can be adjusted forwards and backwards.

A constructional form of the invention is shown by way of example in the accompanying draw- Fig. 1 is a perspective view of the invention as applied to a seat (such as a bus-drivers seat) for enabling the height thereof to be varied, provision also being made for horizontal adjustment backwards or forwards when desired;

Fig. 2 is an enlarged detail of the motion mechanism.

Fig. 3 is a plan showing the invention as applied to horizontal adjustment.

The principle upon which the invention operates will be understood by referring to Figures 1 and 3 where R represents the slidable member (called a slide) which is upon the right side of the seat 0, and L represents the companion slide which is situated at the left side of the seat. These slides R, L are parallel to one another and are slidably movable upon rails A and B which are fixed upon battens D, D behind the slides, '90 when arranged to work in a vertical plane (as in Fig. 1), or the rails A and. B are fixed upon the floor or other object, when arranged to work horizontally (as in Fig. 3), the seat C being fixed to the slides R and L so as to partake of this sliding movement for the purpose of adjustment.

Referring to Fig. 1, the lower end of the slide R is hingedly connected by a crossrod X to a link E hinged to the lower end of the opposite rail B on the other side of the seat C. The

lower end of the rail A is connected by a crossrod Y to a link F hinged to the lower end of the slide L. These crossrods X, Y cross one another at their centre where they are pivoted as at G.

Referring to Fig. 3, the rods X and Y are of the same kind as those shown in Fig. l, but in Fig. 3 they are shown hinged directly to the respective slides and rails without the intervention of links E and F, in place of which the rods X -110 and Y are provided with elongated dots H at one ende which surround pins are studs J, standing up from the rail A and slide R. The rods X, Y in Fig. 3 are connected to the rail B and slide L by simple pivot pins K, K. It will be perceived, that, for example, upward movement of the slide (e. g., R in Fig. 1 or L in Fig. 3) will be efiectively duplicated at the other side of the seat, by reason of the pivoted cross-rods, and it will also be observed that the cross-rods X and Y extend across the space between the slides R and L without requiring any intervening support, so that a clear space is conveniently left behind or underneath them, as the case maybe.

In the form of the invention shown in Fig. l

the provision of horizontal adjustment in addition thereto is optional and the particular mechanism shown in this figure for horizontal adjustment forms no part of my present invention. The seat C is secured directly or indirectly upon brackets Z which are hinged to the slides R, L by hinges M, in any suitable manner. In the arrangement illustratedhinFig. 1, a channelled rail 5 is fastened upon the horizontal portion of each bracket Z. andchannelled slides 3, upon which the seat is directlyfastened by the aid of holes 6, are held inslidable engagement upon said rails 5. A finger piece or catch 12 is provided upon one of of the slides 6, as shown, and controls a lockingdevice ,(notshown) located in the box-like space between the slide 6 and the rail 5.

The, means for raising and lowering the seat consistsas shown in Figs. 1 and 2, of a dome-like crank N fastened to the end of a threaded. rod 0 capable of rotating in a nut P fixed inside the channel of the ra l-A. ,The crank N hasra handle Q and it is rotatably connected to the slide R. .Toenable this to be done, a perforated plate S is fastened byrivetsT to the slide R. The crank N is thereby forced totravel withthe movable slide R, while therail A, secured to battens D, remains stationary Itis therefore clear that the rotationof the crank N raising or lowering slide R, will cause the seat C to rise or fall as a result of the equal distribution of the applied force upon both sides of the seat. The thread upon rod 0 is a square slow thread, in order that the seat will remain automatically locked in the position to which it has been brought when the crank N has finished rotating. In order to increase lateral rigidity the rails 5 are connected across by tierods (not shown). It is obvious that the initial power could be applied through the crank rod connection to the slide L instead of the slide R, through the use of either of the box channels provided by the interengaging slides and rails.

In the arrangement shown in Fig. 3, the horizontal adjustment is performed by mounting the crank N upon the front of the horizontal slide L at the left. hand of the seat. The new position of forward adjustment of the seat C is indicated by dotted lines.

I claim:

1. An adjustable seat mechanism comprising rails and. slides interengaged at opposite sides of the seat, and intersecting connecting means between the rail and slide of one side of the seat and the slide and rail, respectively, of the other side, said connecting means being pivoted at their point of intersection, whereby power applied to one side is distributed equally between the two.

2. An adjustable i seat mechanism as claimed in claim 1, wherein the rails and slides form hollow channel members, within one of which is located actuating means to relatively move the slides and rails, from a point without the said channel member.

3. An adjustable seat mechanism as claimed in 11 claim 1, wherein the rails and slides form hollow channel members, within one of which is located actuating means to relatively move the slides and rails, from a point without the said channel mem- 'ber, which means comprise a nut secured to the rail and a screw working with the nut' and rotatably secured to the slide.

ARTHUR WILLIAM CHAPMAN. 

